xecho.erl

-module(xecho).
-export([listen/0, listen/1]).

listen() ->
    listen(0).

listen(Port) ->
    {ok, S} = gen_tcp:listen(Port, [binary, inet, {reuseaddr,true}, {backlog,1024}]),
    io:format("Listening on: ~p~n", [inet:port(S)]),
    accept(S).

accept(LS) ->
    {ok, S} = gen_tcp:accept(LS),
    Pid = spawn(fun() -> recv(S) end),
    ok = gen_tcp:controlling_process(S, Pid),
    accept(LS).

recv(S) ->
    receive
        {tcp, S, Data} ->
            gen_tcp:send(S, Data),
            recv(S);
        {tcp_closed, S} ->
            ok;
        Error ->
            error_logger:error_report([{socket, S}, {error, Error}])
    end.